Astrophysics
CoPhyLab (Comet Physics Laboratory )
The Comet Physics Laboratory, known as CoPhyLab, is an ambitious collaborative research initiative among Germany, Austria, and Switzerland aimed at exploring cometary processes within the controlled environment of space simulation laboratories.
Dedicated teams of scientists in Braunschweig, Graz, and Bern are actively engaged in the development, construction, and execution of a wide range of experiments. In close collaboration with partner institutions and further experts, we strive to recreate the unique conditions found in comets, including their low densities and temperatures. To achieve this, we have constructed our flagship facility, the "L-chamber," a substantial vacuum chamber equipped with an intricate cooling shield.
While the L chamber, located in Braunschweig, serves as our primary facility, our partners also utilize numerous smaller-scale facilities at their respective institutions. In addition to our experimental efforts, we conduct advanced numerical simulations in parallel to deepen our understanding of cometary processes and their underlying mechanisms.
The scientific goal of my research as part of this project is to elucidate the physical properties governing particle ejection in comets. To achieve this, we focus on a captivating experiment within our CoPhyLab chamber. Here, a granular water ice sample is delicately positioned and bathed in the gentle illumination of a halogenic lamp. As we illuminate and thereby heat the sample, we witness the mesmerizing phenomenon of particle ejection. This captivating phase is meticulously captured by high-speed cameras, enabling us to trace particle trajectories, calculate starting velocities and accelerations, and explore fundamental properties such as gas drag. Already, our efforts have led to the discovery of self-ejection in granular water ice and the existence of non-zero starting velocities.
Our endeavor to comprehend cometary processes through experimentation and precise measurements is crucial for advancing our understanding of the universe. By deciphering the mysteries of comets, we gain profound insights into the formation of celestial bodies and the cosmic mechanisms that shape our existence.
Photo of the experimental setup using a laser light sheet
ICAPS (Interactions in Cosmic and Atmospheric Particle Systems)
ICAPS (Interactions of Cosmic and Atmospheric Particle Systems) is a dedicated research initiative aimed at investigating the intricate interactions and agglomeration of micron-sized dust particles. By delving into the underlying physical processes involved, ICAPS seeks to advance our understanding of the mechanisms that governed the formation of planets during the early stages of the solar system.
The experimental configuration encompasses a meticulously engineered apparatus comprising a vacuum chamber, a silica particle injector, and overview as well as high-speed cameras. This setup enables precise observation and rigorous analysis of the complex interactions among the particles. To facilitate the desired microgravity environment essential for the study of dust aggregation, the entire system is integrated within a sounding rocket, ensuring optimal conditions for precise experimentation and insightful findings.
Sounding rocket launch TEXUS 56
Dust aggregates as seen from one of the overview cameras
My part in this project is the preprocessing and analysis of high-speed recordings of the aggregating dust particles. In this analysis, we focused on the Brownian motion of the dust aggregates and unveiled valuable insights, including the determination of mass, translational response time, moment of inertia, and rotational response time for individual aggregates. Our findings showcased a fascinating correlation between mass and response time, shedding light on aggregate structures with low fractal dimensions. Moreover, we observed slight deviations from pure Gaussian one-dimensional displacement statistics in the ballistic limit, further enriching our understanding of translational and rotational Brownian motion. Therefore, this research significantly contributes to the scientific exploration of particle systems in cosmic environments.
MUSE (Multi-Unit Spectroscopic Explorer)
Sketch of the same galaxy seen at different wavelength using MUSE
MUSE (Multi-Unit Spectroscopic Explorer) represents a revolutionary instrument for advancing our understanding of the universe. With its unprecedented capability to simultaneously acquire high-resolution spectra from multiple locations on celestial objects, MUSE facilitates comprehensive investigations of galaxies, star-forming regions, and individual stars. By precisely capturing light across various wavelengths, MUSE unveils crucial insights into the chemical composition, kinematics, and dynamic processes occurring in distant realms.
During my tenure in Göttingen, I gained valuable experience in analyzing spectrometric data, particularly focusing on MUSE data of diverse Galactic globular clusters (GCs). GCs exhibit captivating abundance variations among their multiple populations, discernible through chromosome maps constructed using Hubble Space Telescope (HST) photometry. However, the limited availability of HST photometry and elemental abundances poses challenges for precise chemical tagging. In our research, we leverage the MUSE spectra of 1115 red giant branch (RGB) stars in NGC 2808, providing a spectroscopic complement to HST photometric catalogs. By categorizing RGB stars into their respective populations and scrutinizing spectral lines, we successfully identify substantial abundance variations in O, Na, Mg, and Al among four populations. Our findings align with previous studies employing high-resolution spectroscopy, underscoring the efficacy of MUSE spectra in investigating abundance variations within the context of multiple populations residing in GCs.